Sintered materials have many advantages in that they can be manufactured through mass production with stable quality and can also adopt a composition unsuitable for smelting materials. Furthermore, sintered materials can be used for manufacturing a porous body. Sintered products which require a little trouble for supplying lubricating oil and can be disposed at a place unsuitable for supplying oil, that is, sintered products suitable for bearings, such as oil retaining bearings in which lubricating oil that has been absorbed inside pores of a porous body can equally exude from a surface, and dry bearings (dry friction bearings) which require no lubricating oil due to graphite or the like contained in material powder with lubricity, are realized by utilizing such properties. Sintered products have been widely used as sintered bearings in the related art (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2004-68074 and Japanese Unexamined Patent Application, First Publication No. 2006-63398).
EGR valves, in which such a sintered bearing is used as a bearing for supporting a valve shaft of an exhaust gas recirculation (EGR) device, for example, and is assembled in a set with a lip seal for the purpose of preventing exhaust gas, liquid, or the like from flowing out in an axial direction of the valve shaft, are known (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2013-7266). Moreover, regarding sintered bearings including a seal for preventing gas or liquid from flowing out in the axial direction, for example, sintered bearings in which a seal member is integrated with a bearing member are known (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2003-202022). In addition, valves including a valve body in which a seal member is integrated with a bearing member are also known (for example, refer to PCT International Publication No. WO2010/018650).